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Minimally invasive surgeries (MIS) are fundamentally constrained by image quality,access to the operative field, and the visualization environment on which thesurgeon relies for real-time information. Although invasive access benefits the patient,it also leads to more challenging procedures, which require better skills andtraining. Endoscopic surgeries rely heavily on 2D interfaces, introducing additionalchallenges due to the loss of depth perception, the lack of 3-Dimensional imaging,and the reduction of degrees of freedom.By using state-of-the-art technology within a distributed computational architecture,it is possible to incorporate multiple sensors, hybrid display devices, and3D visualization algorithms within a exible surgical environment. Such environmentscan assist the surgeon with valuable information that goes far beyond what iscurrently available. In this thesis, we will discuss how 3D visualization and reconstruction,stereo displays, high-resolution display devices, and tracking techniques arekey elements in the next-generation of surgical environments.

Knowledge workers are frequently called upon to perform deep, critical reading involving a heightened level of interaction with the reading media and other tools. This process, known as active reading, entails highlighting, commenting upon, and flipping through a text, in addition to other actions. While paper is traditionally seen as the ideal medium for active reading, computers have recently become comparable to paper through replicating the latter’s affordances. But even paper is not a panacea; it offers an inflexible document representation that supports some things well, such as embellishment, but supports others very poorly, like comparison and large scale annotation. In response to this, I developed a prototype system, called LiquidText, to embody a flexible, high degree-of-freedom visual representation that seeks to alleviate some of the problems in paper and paper-like representations. To provide efficient control of this representation, LiquidText runs on a multi-finger touch and gesture based platform. To guide the development of this system, I conducted a formative study of current active reading practice. I investigated knowledge workers’ active reading habits, perceptions, and the problems they face with current reading media. I also inquired into what they would like in a future active reading environment. I used these results in conjunction with multiple design iterations and formative system evaluations to refine LiquidText for use in a summative study. The summative study assessed, through a controlled, laboratory evaluation, LiquidText’s impact on 1) the subjective experience of active reading, 2) the process of active reading, and 3) the outputs resulting from active reading. Generally, the study found a strong participant preference for LiquidText, and a focus on the creation of a summary of the original document as part of the reading process. On average, reading outputs were not significantly better or worse with LiquidText, but some conditions were observed that may help identify the subset of people for whom LiquidText will result in an improvement.

The purpose of the X-Form package is for use in the classroom as an instructional aid for teaching the algorithms and data used to represent, transform, and display objects in three-dimensional space. The program provides various areas containing graphic and textual representations of the data structures used in the creation and transformation of a three-dimensional object. Another area, containing the menu items, serves as an interface to the available demonstration items. These items include various object and viewing parameters which can be input by the user. The user then sees the result of the entered data, including animated graphics and changes in data structures. The graphic areas show the object at various stages of development, so that the user can understand the progression of the required manipulations. The textual representations are also designed to assist the user in understanding how useful information is derived from entered data. Through testing and statistical analysis, XForm has proven to be an effective tool for instruction of three-dimensional graphics. / Department of Computer Science

Early image understanding seeks to derive analytic representations from image data. This thesis presents steps towards this goal for three-dimensional imagery by focusing on the inference of trace points (points belonging to surfaces), and the estimation of associated differential structure given by the principal curvature and direction fields over smooth surfaces. Computation of these fields is posed as the determination of a cross section through the bundle of curvature frames over the estimated trace. Algorithm robustness and the stability of results are essential for analysis of real images; to this end, I present a functional minimization algorithm where the principal direction cross section meets appropriate criteria for a minimum, and develop an implementation as an iterative constraint satisfaction procedure based on local surface smoothness properties. For shape description and eventual object recognition, the exact recovery of local structure everywhere is less important than the identification of singular surface points which prove stable to noise and small surface perturbations, in particular, the umbilic points of surfaces. Such points are computed naturally from the estimated local surface structure embodied in the principal direction cross section of the frame bundle. Examples of the recovery of local structure are presented for synthetic images degraded by noise and for clinical magnetic resonance images.

A tremendous amount of information is produced in the world around us, both as a product of our daily lives and as artifacts of our everyday work. An emerging area of Human-Computer Interaction (HCI) focuses on helping individuals manage this flood of information. Prior research shows that multiple displays can improve an individual user's ability to deal with large amounts of information, but it is unclear whether these advantages extend for teams of people. This is particularly relevant as more employees are spending large portions of their workdays in meetings My contribution to HCI research is empirical fieldwork and laboratory studies investigating how multiple shared displays improve aspects of teamwork. In particular, I present an insight-based evaluation method for analyzing how teams collaborate on a data-intensive sensemaking task. Using this method, I show how the presence and location of multiple shared displays impacted the meeting process with respect to performance, collaboration, and satisfaction. I also illustrate how multiple shared displays engaged team members who might not have otherwise contributed to the collaboration process. Finally, I present Mimosa, a software tool developed to visualize large volumes of time series data. Mimosa combines aspects of information visualization with data analysis, facilitating a deep and iterative exploration of relationships within large datasets.

Thesis (M.F.A.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 20-26).

Thesis (Ph.D.) -- McMaster University, 1999. / Includes bibliographical references (leaves 98-103). Also available via World Wide Web.

Thesis (Ph.D.)--McMaster University (Canada), 1991. / Source: Dissertation Abstracts International, Volume: 54-02, Section: B, page: 1040.

Thesis (M.S.)--Rochester Institute of Technology, 1990. / "References": leaves 61-63.